Data storage systems are a staple in digital mass storage for back-up and server applications. More specifically they are commonly used to archive data, i.e., store data that is not immediately needed by a host computer. When a host computer needs the data, a request is sent out to the storage system to retrieve the data.
Within the storage system, data is typically archived on physical long term storage media, such as, for example, tape, magnetic disk, optical disc, solid state memory, etc. . . . . When a request is received for data, the storage system identifies the physical long term storage media containing the specified data and a robot transport mechanism is dispatched to retrieve the long term storage media and provide it to a data transfer interface that is capable of establishing a communication path between the storage media and the requesting host computer.
One example of a storage system is a tape cartridge library. In a tape cartridge library, there are typically a plurality of shelves structured to at least temporarily store a tape cartridge. In some instances, the tape cartridges are themselves stored in movable packs that are themselves temporarily stored on shelf structures. The tape library may have more than one drive (data transfer interface) for reading data from and writing data to the tape media within the tape cartridge. Further, the library may have more than one robot operating within the library to transport tape cartridges between the storage shelves and the read/write drives.
Other variations of storage systems utilizing disks, banks of memory chips or other long term storage media are also available. Regardless of the type of storage system, the technology utilized in a storage system may over time become antiquated as faster elements, e.g. storage elements, robots, readers, control systems, processors, etc. . . . are developed. Accordingly, what was a desirable storage system at one point in time, may become less desirable at a later point in time.
For a variety of different reasons, occurrences, such as, modifications or the replacement of a storage system may arise resulting in time periods where data access is limited. It is to innovations related to this subject matter that the claimed invention is generally directed.